What oath did the author give to the land in the Oath of the Land?

The author's oath to the land is: Land, Yuan Ye, my hometown, you must be liberated! You must stand up! & Because I promised her that I would go back to her, I promised that I would definitely go back. & I must see a better hometown appear in front of me-or say that before my grave, I will wash away all her filth and shame with my tears. (The author vowed to fight and die for his hometown) ~